Cable coupler

ABSTRACT

There is provided an improved high voltage cable coupler having a body of integrally cast dielectric polymer chemically formed in situ and having at least one cable receiving channel therethrough. An internal conductor is cast within the body extending within the cable receiving channel to receive the end of a cable. The cable receiving channel is symmetrical, and a cable may be inserted in one end, secured through the other, and the other end then plugged. A soft polymer sealing sleeve advantageously provides air-free interfaces between the cable and the walls of the cable channel, and between the plug and the wall of the cable channel. In a desired embodiment, the soft polymer sealing sleeve is thicker in wall section than the space between the cable and channel so as to form an interference fit between the cable and channel, and between the plug and cable channel wall, so as to resiliently load the soft polymer. At all times, the inner end of the soft polymer is free to move axially into a shielded space, thus permitting a limited range of cable diameters to be used with a given sealing sleeve, and a wide range of cable diameters can be accommodated by employing sealing sleeves of various appropriate wall thickness.

United States Patent Yonkers [54] CABLE COUPLER [72] Inventor: EdwardliYon lrers, Wilmette, Ill.

[73] Assignee: Joslyn Mfg.

Chicago, Ill.

22 Filed: April 12,1971

21 Appl.No.:133,005

and Supply Co.,

[52] US. Cl ..174/72 R, 174/73 R, 174/77 R, 174/88 S, 317/114, 337/168,337/186,

[51] Int. Cl. ..H01r 13/00, H02q 15/00 [58] Field of Search ..174/71 R,72 R, 73 R, 75 R, 174/75 D, 77 R, 80, 84 S, 88 S, 93; 307/147;

339/36, 60 R, 61 R, 94 R, 116 R, 116 C, 143

R, 143 C, 149 R, 150 R, 150 C, 242, 263 R,

1 "20 spam? g9 METAL GRADING |o| FERRULE ELEMENT [151 3,692,921 1 Sept.19, 1972 3,595,984 7/1971 Tachik ..174/72 R Primary Examiner-Laramie E.Askin Attorney-Mason, Kolehmainen, Rathburn & Wyss [5 7] ABSTRACT Thereis provided an improved high voltage cable coupler having a body ofintegrally cast dielectric polymer chemically formed in situ and havingat least one cable receiving channel therethrough. An internal conductoris cast within the body extending within the cable receiving channel toreceive the end of a cable. The cable receiving channel is symmetrical,and a cable may be inserted in one end, secured through the other, andthe other end then plugged. A soft polymer sealing sleeve advantageouslyprovides air-free interfaces between the cable and the walls of thecable channel, and between the plug and the wall of the cable channel.In a desired embodiment, the soft polymer sealing sleeve is thicker inwall section than the space between the cable and channel so as to forman interference fit between the cable and channel, and between the plugand cable channel wall, so as to resiliently load the soft polymer. Atall times, the inner end of the soft polymer is free to move axiallyinto a shielded space, thus permitting a limited range of cablediameters to be used with a given sealing sleeve, and a wide range ofcable diameters can be accommodated by employing sealing sleeves ofvarious appropriate wall thickness.

5 Claims, 20 Drawing Figures CONDUCTlVE GROUNDING n3 SURFACE SPRNGFE'RIFZJJTE GRADING ELEMENT mzmmssmisn 3.692,921

SHEET 1 UF 5 4 & Q C.) 3

INVENTOR EDWARD H. YONKERS 77 1mm, X

BY WM u/W ATTORNEYS PATENTEDSEP 19 1912 3 692 .921

SHEET 2 OF 5 FIG.|2

INVENTOR EDWARD H. YONKERS BY ATTORNEYS PAIENTED EP 1 I912 3.892.921

SHEET U 0F 5 ATTORNEYS PATENTED '9 3.692.921

SHEET 5 OF 5 INVENTOR EDWARD H. YONKERS mow, BY KW 4 4, 0

ATTORNEYS CABLE COUPLER The present invention relates to a cable tapcoupler, and more particularly, to an improved cable tap coupler forjoining, branching and terminating high voltage electric power cable.

The continued rapid growth in the use of electrical energy leads to thenecessity for higher voltages in electrical distribution systems, andparticularly for the electrical distribution systems in highrisebuildings, factories, and the like. For example, over the past 20 years,distribution voltages within buildings have advanced from a five KV zoneto a range of 12 to 15 KV, and present trends point to the 24 and 33 KVdistribution areas. At the same time, the growing requirements forunderground distribution of electricity, particularly in urban areas,has brought about fast improvements in and extensive use of polymerinsulated distribution cable.

The present invention provides new and improved means for convenientlyand securely joining, branching and terminating such distributioncables. The great need for improved means for utilizing distributioncable is clear when one considers the use of the usual pot head and handtaped, joined and branched techniques in terms of a modern,all-electrical highrise building or a large industrial plant where theelectrical energy requirements are so high that the distribution withinthe building or plant requires 12 to 15 KV to avoid excessive conductorcross section. Both high rise buildings and industrial plants todayrequire sectionalizing and branching at frequent intervals, and oftenrequire alternate feed systems in order to avoid long power outages. Onethree-phase alternate feed branch could require as many as 18 of theusual cable terminals. Furthermore, all open terminals and branchswitching points must be housed within a grounded surface for safetyreasons.

Accordingly, it is the object of the present invention to provide a newand improved cable tap coupler.

Another object of the present invention is the provision of a new andimproved system for accomplishing the functions of joining, branchingand terminating electrical distribution cables.

Yet another object of the present invention is the provision of themeans for joining, branching and terminating electrical distributioncables quickly without the use of highly specialized skilled labor.

Still another object of the present invention is the provision of meansfor accomplishing the functions of joining, branching and terminatingelectrical distribution cables with a high degree of circuit integrityand safety.

Further objects of the present invention will become apparent as thefollowing discription proceeds and the features of novelty whichcharacterize the invention will be pointed out with particularlity inthe claims annexed to and forming a part of this specification.

In accordance with the present invention there is provided an improvedhigh voltage cable tap coupler for branching, terminating and couplinghigh voltage cable and including a body of integrally formed dielectric,including a symmetrically formed cable channel extending therethrough.The cable tap coupler includes a low resistance grounding surfacecovering on its body. An internal conductive shunt is cast within thebody extending symmetrically within the cable channel and having anaperture therethrough aligned with the axis of the channel for receivinga cable end means. Thus, a cable end may be inserted in one end of thecable channel, and secured through the other open end thereof. Thisother end then may be plugged to seal the cable channel. In accordancewith one feature of the present invention the body of the cable tapcoupler is formed of integrally cast hard dielectric polymer formed insitu so as to provide a void-free homogeneous dielectric materialwithout folds or weak regions. The polyurethanes represent one suitableclass of materials.

In accordance with another feature of the present invention there isprovided a soft polymer sealing sleeve in each end of the cable channel,so that the cable may be inserted within one end, and a dielectric plugmay be inserted within the other end to form a sealed connection betweenthe cable and the internal conductor. The wall of the soft polymersealing sleeve is greater in radial thickness then the clearance betweenthe cable insulation and the wall of the cable channel, and between theplug and the wall of the cable channel, so as to provide an interferencefit and require elongation of the soft polymer upon insertion of thecable end or plug. Advantageously, the coefficient of expansion of thesoft polymer sealing sleeve, the cable insulation or plug, and hardpolymer forming the body of the cable tap coupler are nearly the same sothat the sleeve remains in void-free engagement during thermal changesof the cable tap coupler; and the initial elongation of the sealingsleeve permits a limited range of cable diameters to be used with agiven sealing sleeve. A wide range of cable diameters can beaccommodated by using sealing sleeves of various appropriate wallthicknesses.

For a better understanding of the present invention reference may be hadto the accompanying drawing wherein:

FIG. 1 is a somewhat schematic view illustrating the simplest form ofinvention known as the type C coupler, functioning as a cable couplingor joint in accordance with the present invention;

FIG. 2 is an end view of the cable tap coupler of FIG.

FIG. 3 is a somewhat schematic view of the invention illustrating a typeBC-branch coupler in accordance with the present invention:

FIG. 4 is an end view of the cable tap coupler of FIG.

FIG. 5 is a somewhat schematic view of the coupler according to thepresent invention wherein one cable is terminated within a groundedsurface housing and connected to an air insulated terminal, referred toas type AT-terminal;

FIG. 6 is an end view of the cable connector of FIG.

FIG. 7 is a somewhat schematic view of yet another form of the inventionwherein 2 cables are joined within the cable tap coupler housing and anair insulated branch terminal is provided, generally referred to as typeATC-Air Terminal Coupler;

FIG. 8 is an end view of the cable tap coupler of FIG.

FIG. 9 is a schematic representation of a cable connector using thetype-C connector of FIGS. 1 and 2;

FIG. is a schematic representation of a threephase branch circuit, usingtype BC connectors of FIGS. 3 and 4;

FIG. 11 is a schematic representation of a 3 phase cable to airtermination using the type AT connector of FIGS. 5 and 6;

FIG. 12 is a schematic representation of a 3 phase cable air tap orbranch using the ATC connectors of FIGS. 7 and 8;

FIG. 13 is a schematic representation of a threephase alternate feedcable air switch in accordance with the present invention;

FIG. 14 is a cutaway view of a typical cable tap connector, here shownas the type ATC form of FIGS. 7 and 8, in accordance with the presentinvention;

FIG. 15 is an end view of the connector of FIG. 14;

FIG. 16 is a plan view of a cable tap connector system illustrating theapplication of the invention which provides the functions of a cablesectionalizing and fused tap or branch circuit as required in a highrise building distribution system;

FIG. 17 is a side view of the system of FIG. 16;

FIG. 18 is a front view of the system of FIG. 17.

FIG. 19 is a side view of the system of FIG. 20; and

FIG. 20 illustrates a top view of a cable tap coupler as would berequired in a high rise building distribution system or the like.

Referring now to the drawings and particularly to the FIGS. 1 and 2,there is illustrated the simplest form of the cable tap coupler systemrepresentative of the present invention and illustrating a typeC-Coupler functioning as a cable coupler or joint connecting the ends ofcables 31 and 32. More specifically, the cable ends having been firstprepared in a manner hereinafter described, and referring to cable 31,the end thereof is inserted into the grounded surface insulated housingof the cable tap coupler 30 through a sealed entrance 33. The cable end31 is bolted to an inner conductor through an opening 34 aligned withthe sealed entrance 33. After the cable 31 has been bolted in place, adielectric plug is inserted in the opening 34 to reestablish seal. Theend of the second cable 32 is inserted into a sealed entrance 35 andsimilarly bolted to the inner conductor through the aligned opening 36which is also then sealed by means of a dielectric plug as in the caseof opening 34. The cable tap coupler 30 is symmetrical so that thecables 31 and 32 may extend out of either end of the respective cablechannels, and the opposite end thereof being plugged. The electricalcircuit in the illustrated embodiment is shown in FIG. 1 by the heavybroken line.

Referring now to FIGS. 3 and 4, the same procedure is followed as withFIGS. 1 and 2, except that the cable tap coupler is illustrated with themore complex type BC-form providing means by which a third'cable may bejoined to the first two cable ends. More specifically, the cableconnector 40 connects the cables 31 and 32 in like manner as heretoforedescribed, cable 31 passing through the opening 33 and then securedthrough the opening 34, cable 32 passing through opening 35 and securedthrough 36. A third cable 41 passes through a sealed entrance 42 and issecured through an opening 43 which is similarly plugged by a suitabledielectric plug. It will be observed that the type-BC cable tap coupleris symmetrical so that the cables 31, 32 and 41 may extend out of eitherend of the respective cable channels. Thus, the branch circuit 41 mayextend to the right, as shown in FIG. 3, or to the left. The electricalcircuit is illustrated by the heavy broken line in FIG. 3.

FIGS. 5 and 6 illustrate a cable coupler 45 of the type AT-air terminalwherein a suitable distribution cable 46 extends into a cable channelthrough a sealed entrance 47 and is secured to an inner conductorthrough an aligned opening 48 in the grounded surface of the cable tapcoupler 45. A suitable dielectric plug closes the opening 48 toestablish the integrity of the cable tap coupler. The inner connector ofthe cable tap coupler 45 is carried to the outside of the housingthrough an extended surface dielectric bushing 49 forming an airinsulated terminal 50. The electrical path is illustrated by the heavybroken line in FIG. 5.

FIGS. 7 and 8 illustrate a type ATC air terminal coupler 55, wherein twocable ends 56 and 57 extend through sealed entrances 58 and 59, ofrespective cable channels, and are secured through aligned openings 60and 61 to an internal conductor in a manner heretofore described. Theinternal conductor is connected to an air insulated terminal 62extending through an extended surface dielectric air bushing'63.

The grounded housing of the cable tap couplers 45 and 55, with the airinsulated terminals 50 and 62, advantageously permit mounting forattachment directly to switch gear frames, switch enclosures and thelike. The versatility of the system is inherent by the fact that allsealed entrances and aligned openings are exactly the same geometry sothat cable entrances or access openings of the cable channels are allinterchangeable, cables extending either to the left or right as viewedin FIGS. 1, 3, 5 and 7.

FIGS. 9 through 13 schematically illustrate various layouts for cabletap coupler system applications of various forms of the invention. Forexample, the type C coupler forms a simple cable coupler or joint asillustrated in FIG. 9. A pair of cables 65, 66 have their endselectrically connected through a type C cable tap coupler 67.

FIG. 10 illustrates the use of a type BC cable tap coupler applied to athree-phase branch system. As therein illustrated a three-phase tap 68a,68b, 68c extends from type BC cable tap couplers 69a, 69b, 69c whichalso couple the three-phase line 70a, 70b, 70c to a threephase line 71a,71b, 71c.

As illustrated in FIG. 11 the type AT cable connectors 72a, 72b, 72c areillustrated providing a threephase cable line 73a, 73b, 73c cable, toair terminals for connection to suitable switch gear or other equipment,not shown.

FIG. 12 illustrates the type ATC cable tap coupler 74a, 74b, 74cproviding an air tap 75a, 75b, 750 to a three-phase line 76a, 76b, 76cand 77a, 77b, 77c.

Referring now to FIG. 13 there is illustrated a threephase alternatefeed air switch including a set of threephase branch terminals 78a, 78b,78c which may be selectively connected to a first set of feed lines 79a,79b, 79c or a second set of feed lines 80a, 80b, 80c by means ofsuitable switch blades 81a, 81b, 81c. The first set of feed lines 79a,79b, 79c connect through suitable type ATC cable tap coupler 82a, 82b,82c to lines 83a, 83b, 83c. The second set of feed lines 80a, 80b, 80c

connect through suitable ATC type cable tap couplers 84a, 84b, 84c tofeed lines 85a, 85b, 85c. The switch blade 81a, 81b, 810 willselectively connect the tap terminals 78a, 78b, 78c with the airterminals of the first set of cable tap couplers 82a, 82b, 820 asillustrated in solid in FIG. 13, or to the second set of cable tapcouplers 84a, 84b, 84c as illustrated in phantom in FIG. 13.

A typical cable tap coupler is illustrated in FIGS. 14 and 15. Astherein illustrated the cable tap coupler is of the ACT type shown inFIGS. 7 and 8 wherein 2 cables are joined or coupled with an airtenninal tap. This fonn of cable tap coupler is illustrated as typicalof the other forms, for example, the type C, BC, and type AT, andsimilar components of the ATC air terminal coupler will be identicalwith those of the other types. FIG. 14 illustrates in broken awaysection through the axis of one of the cable channels a typical cableattachment to the cable tap coupler, and is taken substantially alongthe vertical plane 14-14 of FIG. 15.

As therein illustrated there is shown a cable connector 89 having a body90 of'a dielectric material. It has been found that an integrally castdielectric polymer formed in situ possesses the desirable mechanical andelectrical properties such that there are no discontinuities, folds orvoids in the polymer which would give rise to electrical weakness, andis tough and rigid to support mechanical couplings. The dielectric body90 is formed with a pair of through cable channels 91, only one of whichis illustrated in broken away section in FIG. 14, and an exposed airterminal 92 extending through an extended surface dielectric bushing 93.

The cable tap coupler is here illustrated as applied to a soliddielectric grounded sheath type of electrical power cable 95, 96 but thecable tap coupler is equally applicable to concentric neutral typecables with the addition of connection means for its neutral wires. Eachof the cables 95, 96 has been prepared and secured within the cable tapcoupler 89 in a similar manner and accordingly, only the preparation andinsulation of the cable 95 is herein described as typical. Referring nowto the cable 95, the cable has been prepared by removing an outer jacket97 a prescribed distance from the end 95a thereof so that a desiredamount of a conductive wound taped shield 98 is exposed. Cableinsulation 99 is exposed beyond the shield 98 a predetermined distanceexposing a central conductor 100 of the cable 95. A compressionconnector 101 is secured over the end of the central conductor 100 inany suitable manner, such as by crimping. The compression connector 101is provided with a threaded end 102.

To provide for the electrical path between the various cables andterminals of the couplers, there is provided an internal conductor 105extending from the air terminal 92 through the cable connector 89 andinto the respective cable channels 91. Within the cable channels 91 theinternal conductor 105 is provided with a suitable aperture 106 forreceiving the threaded end 102 of the compression connector 101. Theedges of the aperture 106 are beveled or chamfered, such as at 106a, tomate with a complementary taper 101a on the compression conductor 101providing good electrical and mechanical connection between thecompression connector 101 and the inner conductor 105.

The cable tap coupler 89 is symmetrical as to its left and right sideswith the internal conductor 105 centrally positioned within the channels91 so that the cables 95 and 96 may be inserted and assembled fromeither side of the respective cable channels 91.

The cable tap coupler 89 is cast with the dielectric body and isprovided with a low resistance grounded housing surface 111 of stainlesssteel or other suitable conducting material. Metal inserts 112are(molded or) cast within the dielectric body 90 concentric with eachend of the cable channels 91 and from an extension of the cablechannels. The grounded surface 1 1 1 contains a central opening,defining a metal flange 113 which contains suitable threaded bolt holesfor mounting the unit onto switch frames or other suitable structure tothe grounded surfaces of such housings for various applications. Theexterior metal housing is firmly held together by means of end covers114, 115 and tension rods 116 and nuts 117. The internal conductor 105is cast in place with the dielectric body 90 securing the same invoid-free contact therewith. Suitable circular garter spring connectors119 provide a good conductive path from the taped shield 98 of the cableto the ground through the adjacent metal insert 112.

To provide for electrically insulating and sealing the cable channels91, there is provided a pair of soft polymer sealing sleeves 128, 128each formed with a metal ferrule 129, 129' and a spring grading element130, 130' embedded in the polymer. An outer flange 131, 131' formed onthe metal ferrule 129, 129' engages the end of the threaded insert 112at its outer edge thereby positioning the respective sealing sleeves128, 128 within the ends of the cable channels 91.

Prior to assembly of the cable 95 into the cable channel 91 a cap 125having a sealing gasket 126 is slipped over the outer cable jacket 97.The spring connector 119 is also slipped over the cable end so as toengage the grounding tap shield 98. The cable is then inserted into thedesired end of the cable channel 91 through the soft polymer sealingsleeve 128. The radial thickness of the sealing sleeve 128 is greaterthan the clearance between the cable insulation 99 and the inner surfaceof the cable channel 91 so that the sleeve 128 will elongate axiallyaway from the restrained end as the cable is forced into the opening,thus subjecting the sleeve 128 to a compression and thereby wiping theinterfaces between the cable insulation 99 and the soft polymer sleeve,and between the soft polymer sleeve and the inner surface of the cablechannel 91 completely free of air, and providing an air free interfacebetween these surfaces. Sufficient open space is provided beyond theends of the polymer sleeve 128 and the internal conductor to permit aconsiderable range of cable insulation outer diameters to be received sothat a limited range of types and sizes of cables may be employed with aparticular sleeve and a wide range of cable sizes can be accommodatedwith several sleeve sizes. The connector 101 has its threaded portion102 inserted through the aperture 106 in the internal conductor 105 andis bolted firmly in place by means of a nut 122 and a Belleville springwasher 123. The nut 122 may be tightened with a socket wrench throughthe opposite or open end of the cable channel 91. The cap may then betightened to provide a permanent seal against air and moisture withoutthe use of mechanical spring means since the elastic stress in thepolymer 128 is sufficient to maintain the necessary void-freeinterfaces. Moreover, because the thermal coefficient of expansion ofthe polymer sleeve 128, the cable insulation 99, and the dielectric body90 are very nearly the same, they will not be subjected to alternaterelative expansion and contraction due to thermal changes in the cabletap coupler 89. The interfaces of the associated members including thecable insulation 99, the polymer sealing sleeve 128 and the dielectricbody 90 are coated with silicone grease before assembly in order toreduce friction and to assure the gas free interfacial engagementtherebetween.

The same sealing system generally is employed at the free or open end ofthe cable channel 91. More specifically, a dielectric plug 135 isprovided having an outer diameter slightly greater than the innerdiameter of the sleeve 128 in like manner as the cable insulation 99 soas to elongate the soft polymer along the axial direction away from theretaining flange 131 thereby permitting the oversized plug to enter thesleeve. Thus, the sleeve 128' is pre-stressed progressively along itsaxial length to expel air between the interfaces between the dielectricplug 135 and sleeve 128, and between the sleeve 128' and dielectric body90. There is provided a completely air free interfacial engagementbetween the components. The necessary volumetric change in the sealingsleeve 128' takes place in like manner as with the sealing sleeve 128 bythe extension of the outer end of the sleeve 128 into the space adjacentthe internal shunt 105. An air vent rod 136 is then inserted into an airvent opening 135a extending axially through the dielectric plug 135. Asealing cap 137 and sealing gasket 138 are then threaded onto the metalinsert 112 and the opening to the cable channel 91 is closed.

The interfaces of the associated members including the dielectric body90, the sealing sleeve 128', the dielectric plug 135 and the air ventplug 136 are coated with silicone grease before assembly in order toreduce friction and assure gas free interfacial engagement. The air ventrod 136 is inserted after the plug 135 is in place so as to minimize thevolume of entrapped air within the cable channel 91.

The described system becomes a permanent seal against air and moistureinfiltration without the use of additional spring members to spring loadthe polymer sleeves because of the elastic strain on the polymer sleeves128, 128, and further because the thermal coefficient of expansionbetween the polymer sleeves 128, 128', the dielectric body 90, and thecable insulation 99 or dielectric plug 135 are very nearly the same.

In order to prevent electrostatic field effects in the air space withinthe cable channels 91 around the internal conductor 105, a conductivecoating 140 is employed on the dielectric body surface and connected tothe internal conductor 105. The outer edges of the conductive lining 140extend into the air free interfacial zones between the sealing sleeves128, 128', and the dielectric body 90 where the maximum potentialgradient occurs. Potential gradients occuring within the air spaces arethus reduced to insignificant levels. The potential gradients arereduced in the air excluded regions at the outer ends of the openings bymeans of conical geometry of the inner ends of the metal inserts 112, asshown at 1 12a, and by the ferrule 129, 129'.

Both of the end openings of the cable channels 91 providing for cableentrances or access holes are geometrically and electrically the same,so that the sealing sleeves 128, 128', plugs 135, and caps 125, 137 areinterchangeable both as between the ends of the cable channel and asbetween cable channels of a cable tap coupler. This versatility isimportant in many applications.

The air terminal 92 is an extension of the internal conductor and theair insulator or dielectric bushing 93 is an extension of the integraldielectric casting forming the dielectric body 90 so that there is nodiscontinuity or interfacial seal in the dielectric envelope over thehigh potential conductive elements of the cable and the associatedconductor. The dielectric bushing 93 is to have sufficientgeometricextension to provide adequate space and leakage surface for theintended voltage.

All external surfaces of the integral dielectric casting or body 90excepting the extended surface dielectric bushing 93 are coated with aconductive material, locked gas free into the surface of the dielectricbody 90. This removes the necessity for the metal grounded surface 111to fit the dielectric exterior in void-free relation. Small areacontacts between the grounded surface 1 l1 and the dielectric body 90without the conductive surface could cause destructive corona and radiointerference from such causes.

The strong metal flange 113 provides for mounting the unit on switchframes or through the surface of grounded housings for variousapplications. The exterior metal housing is firmly held together bymeans of the end covers 114, 115 and the tension rods and nuts 1'16,117. The mechanical integrity of the system is sufficiently strong sothat the air terminal 92 can be connected to fittings suitable forforming receivers or switch blades, fuse clips and the like.

FIGS. 16 and 17 illustrate the type AT couplers 45 illustrated in FIGS.5 and 6, and forming disconnecting switches and fuse disconnects in aswitching center 144, suitable for use in a highrise building l5 KVdistribution system and the like. Accordingly, the same referencenumerals will be used in FIGS. 16 and 17 to identify identical partswith the embodiment of FIGS. 5 and 6. The switch housing 144 includes 3AT type cable tap couplers 45, and three associated stand-off insulatedterminals 145, all mounted to the switch center 144 through flanges 146on the cable tap couplers 45 and flanges 147 on the standoff insulatorterminals 145. The stand-off insulator terminals have projecting airterminals 148 interconnected by a suitable buss 149. The air terminal 50on the cable tap coupler 45 serves to directly mount the hinge 151 of aswitch blade 152 or to directly receive a fuse 153. Thus, there isprovided from a supply line 154 a switched line 155 and a fused tap 156.

Advantageously, there may be provided an isolating barrier, shown inphantom at 157 in FIG. 16, and in sertable between the terminals 50 and148 when the switch blade 152 is open or removed. The barrier may have acolored sight indicator 157a visible through a window or sight glass158, FIG. 17, formed in the cover of the housing 144. The barrier 157may be slid into place between a pair of opposed grooves 144b formed bypairs of ribs 144a in each compartment of the housing. Thus, aServiceman can readily observe by sight whether a particular circuit hasbeen electrically isolated.

FIGS. l8, l9, and 20 illustrate a typical fused tap from a through lineand illustrates a type ATC coupler tap connector 55, similar to thecable tap coupler 55 illustrated in FIGS. 7 and 8, and an AT type cabletap coupler 45 similar to the cable tap coupler described in FIGS. and6. More specifically, the cable tap couplers 45 and 55 are secureddirectly to the bottom of a fuse box 159, with their air terminals 62,50 opening into the interior of the box. A suitable fuse 160 is mounteddirectlybetween the air terminals 62 and 50. A supply line 161, 162extends through the cable tap coupler 55, and a tap 163 extends from thecable tap coupler 45. The heavy phantom lines represent the paths ofcurrent flow.

Advantageously the air terminal embodiments provide for an air bushinghaving a strong mounting flange and, when installed in a service box,the inner air bushing is isolated from the externally accessible cablecoupling or receiving portion. Moreover, the coupler is reusable; thesame or another cable may be repeated, removed or reassembled with thecable coupler.

Although the present invention has been described by reference toseveral embodiments thereof, it will be apparent that numerous othermodifications and embodiments will be devised by those skilled in theart which will fall within the true spirit and scope of the presentinvention.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

l. A device for coupling a high voltage cable with associated apparatuscomprising:

a body of integrally formed dielectric material having a channelextending therethrough,

a low-resistance grounding surface covering a major portion of saidbody,

first means within said channel conductively receiving an end of saidcable,

second means within a first end of said channel receiving andmaintaining in a void-free interfacial relationship an insulated portionof said cable, dielectric means for closing and sealing a second end ofsaid channel,

third means within said second end of said channel receiving andmaintaining in a void-free interfacial relationship said dielectricmeans and a bushing extending outwardly from said device through saidgrounding surface, formed by a portion of said body of integrally formeddielectric material and including fourth means conductively connected tosaid first means for electrically connecting said cable to saidassociated apparatus.

2. A device as recited in claim 1 wherein said second and third meanscomprise soft dielectric sealing sleeves elongated axially andcircumferentially distorted and stressed upon the receipt of saidinsulated portion of said cable and said dielectric means, respectively,to maintain said insulated portion of said cable and said dielectricmeans in said void-free interfacial relationships within said channel.

3. A device as recited in claim 1 wherein said dielectric meanscomprises a dielectric plug having a longitudinally extending air ventand means for sealing said air ve t.

2. A device as recited in claim 1 further comprising conductive meansaffixed to a portion of that part of said body forming said channel,conductively connected to said first means for reducing the electricalstress on the air trapped within said channel.

5. A device for terminating the end of a high voltage cable comprising abody of dielectric material, a channel extending through at least aportion of said body, means within said channel receiving andmaintaining in a void-free interfacial relationship an insulated portionof said cable, said means comprising a soft dielectric sealing sleeveelongated axially and circumferentially distorted and stressed upon thereceipt of said insulated portion of said cable to maintain saidinsulated portion of said cable in said void-free interfacialrelationship within said channel, and means holding one end of saidsleeve in place within said channel.

2. A device as recited in claim 1 wherein said second and third meanscomprise soft dielectric sealing sleeves elongated axially andcircumferentially distorted and stressed upon the receipt of saidinsulated portion of said cable and said dielectric means, respectively,to maintain said insulated portion of said cable and said dielectricmeans in said void-free interfacial relationships within said channel.3. A device as recited in claim 1 wherein said dielectric meanscomprises a dielectric plug having a longitudinally extending air ventand means for sealing said air vent.
 4. A device as recited in claim 1further comprising conductive means affixed to a portion of that part ofsaid body forming said channel, conductively connected to said firstmeans for reducing the electrical stress on the air trapped within saidchannel.
 5. A device for terminating the end of a high voltage cablecomprising a body of dielectric material, a channel extending through atleast a portion of said body, means within said channel receiving andmaintaining in a void-free interfacial relationship an insulated portionof said cable, said means comprising a soft dielectric sealing sleeveelongated axially and circumferentially distorted and stressed upon thereceipt of said insulated portion of said cable to maintain saidinsulated portion of said cable in said void-free interfacialrelationship within said channel, and means holding one end of saidsleeve in place within said channel.